io.github.cyanheads/cern-opendata-mcp-server
cern-opendata-mcp-server
Search CERN Open Data, fetch records, files, analysis environments, CMS good-run lists, HLT paths.
alive probed 2026-10-05 · HTTP 200
7tools
6.3ktokens in Claude Opus 5.5
6.4ktokens in Claude Code
3.2 %of a 200k context window
3.9ko200k_base estimate
459 msto initialize
106 msto list tools
- Endpoint
- https://cern-opendata.caseyjhand.com/mcp (streamable-http)
- Host
- cern-opendata.caseyjhand.com
- Protocol
- 2025-11-25
- Reports itself as
- cern-opendata-mcp-server 0.2.0
- Capabilities
- logging, prompts, resources, tools
- Instructions
- 1 538 characters
- Claude count
- Claude Opus 5.5, measured 2026-10-05. Counted again when the tool definitions change. Method.
- Repository
- https://github.com/cyanheads/cern-opendata-mcp-server
- Registry
- active, updated 2026-10-02 · registry entry
- Reachable
- 6 of the last 6 probes
Most expensive tools
| Tool | Tokens (o200k) | Share of this server |
|---|---|---|
| cern_opendata_search_records | 1 567 | 40 % |
| cern_opendata_search_trigger_paths | 592 | 15 % |
| cern_opendata_get_validated_runs | 508 | 13 % |
| cern_opendata_get_records | 467 | 12 % |
| cern_opendata_list_files | 344 | 9 % |
History
We add a row when the result changes. A server with no change keeps its last row.
| Probed | Result | Init | Tools | Claude | o200k |
|---|---|---|---|---|---|
| 2026-10-05 14:38 | alive | 459 ms | 7 | 6.3k | 3.9k |
| 2026-10-05 00:33 | alive | 307 ms | 7 | 3.9k | |
| 2026-10-04 10:04 | alive | 868 ms | 7 | 3.9k | |
| 2026-10-04 07:57 | alive | 580 ms | 7 | 3.9k | |
| 2026-10-03 20:37 | alive | 1.3 s | 7 | 3.9k | |
| 2026-10-03 17:53 | alive | 572 ms | 7 | 3.9k |
Badge and feed
[](https://mcpcost.ulehla.dev/s/io.github.cyanheads/cern-opendata-mcp-server)
An entry for every probe that changed the result, the tool count or the token cost: Atom feed. Add it to a feed reader or a Slack RSS app to hear when the server stops answering or its tool set grows.